Clear Cell Acanthoma
Author: Dr Amy Prideaux
Chief Editor: Dr Daniel Keith
Also known as Degos Acanthoma!
Macroscopic Appearance
A clear cell acanthoma is a rare type of benign epithelial skin tumour with a very characteristic dermoscopic finding. You are unlikely to come across these lesions on a regular basis, but when you do they will be easy to spot! Onset is usually in adulthood, and lesions may slowly enlarge over time. The thin surface crust can occasionally bleed and ooze when disrupted or removed, which may be something mentioned in the history.
Classically, a clear cell acanthoma is:
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Raised (can be a nodule or plaque)
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Pink-brown in colour
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Often scaly on the surface
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Usually solitary on the lower limbs
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Up to 2cm in size
Dermoscopic Appearance
Dermoscopically, the characteristic pattern associated with clear cell acanthomas is the 'string of pearls'.
This is created by the arrangement of blood vessels lined up in strings, which is illustrated very nicely in this example.
Below are further examples of a clear cell acanthomas (macroscopic and dermoscopic), courtesy of Samantha Wells, MacMillan Skin Cancer Nurse.
Macroscopic view depicting a pink, nodular lesion with a thin surface scale.
Dermoscopic view illustrating the string of pearls pattern of blood vessels.
Macroscopic localising image
Macroscopic close up
Dermoscopic